friend



E. H. FRIEND. ROTARY ENGINE.

APPLICATION FllED FEB. 2. 1919- 1,307,903. Patented June 24,1919.

4 SHEETS-SHEET l.

E. H. FRIEND.

ROTARY EVGHJE.

APPLICATlON FILED FEB. 3. m9.

Patented June 24, 1919.

4 SHEETS-SHEET 2.

E. HIFRIEND.

ROTARY ENGINE.

APPLICATION FILED FEB. 3. I9l9. 1 7 03, 1 Patented June 24,1919.

4 SHEETS-SHEET 3.

E. H FRIEND.

ROTARY ENGINE.

APPLICATION FILED FEES-1919.

Patented June 24, 1919.

4 SHEETS-"SHEET 4 EDWARD HENRY FRIEND, OF LONDON, ENGLAND.

ROTARY ENGINE.

Specification of Letters Patent. Patented June 24, 1919 Application filed February 3, 1919. Serial No. 274,771.

To all whom it may concern lie it known that I, EDWARD HENRY lFmuNn, a subject of the King of Great Brit ain, residing at Bangor Hotel, 18 Upper Woburu llace, Russell Square, W. C. 1, in the county of London, England, have invented certain new and useful Improvements in or Relating to Rotary Engines, of which the following is a specification.

This invention relates to rotary engines of the annular chamber type, in which movable vanes or abutments carried by the rotary member are rocked or moved durino the rotation of the latter to pass by fixer parts 01' pistons on the stationary member. The chief object of the present invention is to provide an improved engine of this type comprising several novel features of construction which enable a comparatively light engine of high power to be produced particularly though not exclusively for the purpose of propelling aircraft. The improved engine may be constructed as an 111- ternal combustion engine but the general features of construction are also applicable to a steam operated engine.

According to this invention, the stationary member is provided with diametrically opposite pairs of fixed pistons, each pair fitting within annular chambers in the rotary member forming the main or outer casing of the engine, and carrying movable vanes or abutments with means for moving them simultaneously out of the way of the fixed pistons, during the rotation of the rotary member, which means are actuated by engagin with suitable parts on the stationary member. Vhen the invention is applied to internal combustion engines, two sets of fixed pistons on the stationary member may be employed, one set cooperating with certain of the said abutments and constituting the main or power pistons, situated in the power chambers of the rotary memher while the other set situated in the compressor chambers of the rotary member and cooperating with other abutments, may serve for the purpose of drawing in and compressing the gaseous mixture and supplying it to the power chambers. The gaseous mixture may however be supplied to the power chambers in any appropriate manner. The stationary member which is of annular form carries a set of power pistons and a set of compressor pistons on each side and the rotary member may comprise two parts each having concentric chambers in which are disposed the power and compressor pistons on each side of the stationary member, the two parts of the rotary member being adapted to rotate as one member,'and each part carrying the movable abutments for cooperating with the pistons on each side of thestationary member. An improved construction of actuating gear is mounted on each part of the rotary member for moving the abutments during the rotation of this member which construction is also applicable in the case of a steam operated engine. A turbine may be combined with the engine so as to constitute part of the latter, and in the case of a rotary internal combustion engine the construction and arrangement may be such that after each impulse produced by the explosion of a gaseous charge between the power pistons and the respective abutments, the products of combustion are expelled from the power chamber into a chamber containing a. series of blades or the like fixed on the rotary member and thence to atmosphere. This ar- I-(ngement thus provides an exhaust operated turbine which increases the power of the engine and at the same time serves as a silencer. The feature combining a silencer with the engine is particularly advantagGOllS in the case of an aeroplane engine, as the necessity of a separate silencer is avoided, the turbine not only servingas an efficient silencer, but enabling increased power to be obtained without materially increasing the weight of the engine. Provision is made for cooling the engine by water or air or both and for lubricating the working parts and the various pipes or connections for conveying the cooling water and the lubricant are attached to the stationary member as also are the sparking plugs and electrical connections, thus avoiding complications in construction which would arise if the various connections were attached to the rotary member. When the engine is adapted for aircraft propulsion, a propeller may be mounted on each part of the rotary member so as to constitute front and rear propellers which may be arranged at 90 to each other.

In order that the said invention may be clearly understood and readily carried into effect, I will describe the same more fully with reference to the. accompanying drawings, in which Figure 1 is a longitudinal sectional view use on aircraft.

Figs. :2 and 3 are transverse sectional views taken respectively on the line 2, 2 and the line 3. 3 of Fig. 1.

Fig. 4 is an exterior rear view of the engine with the rear propeller removed, the view being taken on line -ll of Fig. 1.

Fig. 5 is a fragmentary longitudinal sectional view taken approximately on the line 55 of Fig. 2, but drawn to a slightly larger scale.

Fig. (3 is a sectional view taken approximately on the line 66 of Fig. 5 but drawn to a smaller stale than Fig. 5.

Fig. 7 is a fragmentary longitudinal sectional view showing the communication between one compressor chamber on one side of the stationary member to the power chamber on the other side of the stationary member.

Fig. 8 is a fragmentary view similar to Fig. 3. showing the position of one pair of the aforesaid abutments relatively to one of the power pistons and one of the compressor pistons at the commencement of the explosion or power stroke.

Fig. 9 is a sectional view of one of the power pistons.

Fig. 10 is a side view of one pair of rods forming part of the actuating gear employed for operating the abutments, one of the rods being shown in section.

Fig. 11 is a diagram hereinafter explained in connection with operation or working of the engine.

In the embodiment of the invention illustrated, A is the stationary member in the form of a ring-like structure or casting on each side of which lateral extensions are provided to form two oppositely disposed power pistons A A and two oppositely disposed compressor pistons A A on each side of the said ring-like structure A. The rotary member of the engine comprises two circular ring-like parts or casings B. B each having an outer annular groove B and an inner annular groove B to receive respectively the power pistons A and the compressor pistons A on each side of the stationary member A, the two parts B, B being fitted laterally on to the said pistons A, A. A A and secured in position by being bolted to flanged rings B having inclined faces to fit on or engage with correspondingly inclined faces on the stationary memher A. The flanged rings B are each preferably constructed in two portions or halves, and the said inclined faces permit of the parts B, B being drawn tightly on to the said pistons and also enable adjustment to be effected to compensate for any slackness between the rotary and stationary members as a result of wear. The two parts B when secured around the stationary member A as aforesaid, constitute a single member which forms the rotary member or casing of the engine, which member or casing rotates on two ball bearings, C, C disposed between it and two fixed lateral extensions A, A extending from the two sides of the stationary member A, the said extensions A surrounding a central axial passage through the engine (see Fig. 1). The oppositely disposed power pistons A, A on one side of the stationary member A are arranged at 90 with respect to the corresponding pistons on the other side of the stationary member, and the compressor pistons A A are similarly arranged w1th regard to each' other, but in different radial planes from the power pistons, (see Fig. 3).

Each part B of the rotary member or casing is formed at oppositely disposed parts to receive plugs or disks D, the oppositely disposed plugs or disks D on one member B being arranged at 90 degrees relatively to the oppositely disposed pair of plugs or disks D on the other part B, (see Figs. 3 and 4) and each disk D is mounted so as to be angularly moved or oscillated. ()n the inner face of each disk D are provided two oppositely disposed segmental parts (herein termed the abutments D. D which project into curved slots B in the rotary part B and are adapted to normally lie in or across the power chambers B and the compressor chambers B respectively, but are adapted to be angularly moved by oscillating the disks D so that they become completely housed in the curved slots B during the rotation of the member or casing B B in order that the said abutments may move out of-the way of the fixed pistons. The abutments D are the power" almtments which cooperate with the power pistons A and the abutments D are the compressor" abutments which cooperate with the compressor pistons A In order to effect the angular movement of the said disks 1) and the abutments D. D thereon. each oppositely disposed pair of disks D I) mav be connected together by a pair of rods E. E. the ends E of which loosely surround projections on the outer faces of the disks I). the said cross rods E, ha'ving rollers or projections E thereon adapted to engage with oppositely disposed cam surfaces A formed on the extremities of the lateral extensions A of the stationary member A so that during the rotation of the member of casing B carrying with it the cross rods. the latter are displaced by the fixed cams A laterally and longitudinally as to cause the oscillation of the disks D so that the abutments thereon are positively moved out of the )ower chambers and the compressor chain ers are re quired during the cycle of operations of the engine against the action of springs E (see Fig. 4') which normally retain the rods E in such positions as to maintain the abutments out of their slots so that they lie in or across the power and compressor chambers, and project in small slots B formed in the parts B B of the rotary member or casing, see Figs. 3 and 8. When the abutments l), I) lie in the power and compressor chambers B, B the spaces between the rear faces of the power abutments D, and the front faces of the power pistons A constitute the spaces in which gaseous mixture is exploded, while the spaces between the front faces of the power abutments D and rear faces of the power pistons A constitute the spaces from which the products of combustion are expelled through ports B in the rotary member during the rotation of the latter. The compressor abutments D form with relation to the compressor pistons A suction spaces between their rear faces and the front faces of the pistons A into which the compressed mixture is drawn, while the spaces between the front faces of the said compressor abutments D and the rear faces of the compressor pistons A are the spaces in which the mixture is compressed and afterward transformed to the power chamber A at the opposite side of the engine through cross ports A in the stationary member A (see Fig. 7) as hereinafter described. Each part of the rotary member or casing B is provided on its exterior peripheral surface with a series of inclined blades B which are surrounded by a spun copper casing B secured to each member of the casing, see Figs. 1 and 3. The blades 13 are staggered as shown in Fig. 3 by forming each alternate blade with a transverse slot or slots at the outer part and by forming the intervening blades with a transverse slot or slots at the inner parts, these slots providing a staggered passage for the exhaust gases which are expelled from the power chambers B through the ports B and after passing the blades escape to atmosphere through an opening B in the spun copper casing B, see Figs. 3 and 8. The blades arranged as shown serve as combined guide and power blades or vanes. This arrangement therefore forins an exhaust operated turbine which increases the power output of the engine and the blades assist in breaking up the exhaust gases so as to produce a silencing effect. From the foregoing description it will be observed that the engine comprises two parts arranged one on each side of the stationary member or middle ring A, with similar cooperating or working parts on each side but arranged at 90 relatively to each other.

The engine may be supported on the planes or wings of an aeroplane say one or more on each side of the fuselage by means of four equi-distant lugs or projections A on the stationary member or middle ring A see Figs. 1 and 2. Each part B of the rotary member or casing may carry a propeller F and in the example shown, each propeller is two bladed and is provided with two bosses F connected by a middle portion F the bosses F of each propeller bein attached to the rotary parts of the casingfi? by means of a number of bolts F disposed around the portions of the casin in which the abutment disks D are mounted, see Figs. 1 and 4;. The propeller F on one side is arranged at 90 degrees to the propeller on the other side as shown more particulary in Fig. 1, and the bolts F supporting the propellers may be extended to any suitable distance to the front and rear of the engine. Alternatively, each propeller may be provided with 'a central boss which may be attached to a suitable mounting on the rotary member of the engine around the axial passage formed therein or the propellers may be mounted around the exterior or peripheral parts of the rotary casing B.

In the example shown the gaseous mixture is supplied to the engine from a carbureter or carbureters through pipes G controlled by non return valves (not shown) and connected to the stationary member or ring A which pipes communicate with the compressor chambers B on each side of the stationary member by ports G, see Fig. 3. During the rotation of the member or casingB,the caseous mixture is drawn into the chambers B through the pipes G and ports ,ir" by the suction produced between the compressor abutments D and the compressor pistons A see Fig. 8, owing to the in crease in size of the space between the rear faces of the said abutments and the front faces of the compressor pistons A during the rotation of the member or casing B carrying the abutments, while the mixture drawn in by thecompressor abutments D is compressed between the front faces thereof and the. rear faces of the compressor pistons A in each of the compressor chambers B and at the requisite time is forced from each chamber B through the cross ports A in the stationary member leading into the power chamber at the opposite side of the engine, these cross ports being controlled by valves formed by circular parts 13 on the rotary members B, B having two diametrically opposite openings B therein see Figs. 5 and 6 which register with the cross ports A during the rotation of the member B to permit of the transfer of the compressed mixture from the compressor chamber B on one side of the engine to the power chamber B at the other side as aforesaid, see Figs. 6, 7 and 8. Adjacent to thefront face of each power piston A is a. sparking plug H which is screwed into the stationary member so as to project into the cross port A on the outside of the aforesaid ring valve B as shown in Fig. 5. In order to effect the water cooling of the engine an inlet pipe J is connected to a port in the stationary member from which the water circulates through a passage J formed around the said stationary member, which passage is in communication with suitable assages J 2 in each power piston A so that t 1e pistons may be water cooled. an outlet port J being provided in the said stationary member A, see Fig. 2; the water passage in the stationary member is closed by means of a division piece J 4 located between the inlet and outlet ports as shown in Fig. 2. Provision may also be made for air cooling in which case a deflector A see Fig. 1 may be provided at the middle part of the stationary member to direct the air into suitable ports or passa es in the stationary member. Moreover sultable radial fins B as shown in Figs. 1 and 4 are provided on the exterior of the rotary member casing and they extend into passages between the compressor chamber and the working chamber in each part of the rotary member B as shown in Fi 1. Lubricating oil is conveyed to the stationary member A through a port K, see Fig. 2, which ort K is in communication with passages I lead- 30 ing to the interior of the compressor and I power pistons. In most instances the engaging or contacting surfaces between the rotary and stationary parts of the engine are of tapered or wedged formation to enable the parts to be adjusted or are set to take up or compensate for wear. During manufacture heat grinding is resorted to so as to produce satisfactory engaging and contacting surfaces which will prevent leakage between them. The heat grinding is effected by grinding the tapered engaging surfaces together with emery powder or ground glass between the surfaces, the heat being produced by the friction set up or by other means. As an additional precaution against 'leakage the surfaces of the engine pistons which contact with the rotary casing B may be formed with a series of inclined slots K see Fig. 9, incommunication with the oil 60' passage K in the pistons A and by injecting oil under pressure into the pistons it will emerge through the inclined slots K between the contacting surfaces of the pistons and the rotary member or casing B in the same direction as that of the rotation of the member B so that an effective gas joint or seal is provided. The general construc- -tion and arrangement of one form of the engine having been described I will now describe the operation of the same. As previously explained the abutments D D are normally maintained in the position shown in Figs. 8 and ll'by means of the spring controlled actuating rods E. In .5 order to start the engine, the member or casing B is rotated by hand or by a mechanical or electrical starter. Assuming each set of the abutments D D to be in the position relatively to the respective pistons A A as shown in F 1g. 8, the rotation of the casing in the direction of the arrows indicated in the various Figs. 3, 4. 8, and 1 1 the abutments D in being carried around with the casing B move away from the fixed compressor pistons A and thus produce a suction effect between the rear face or side of the abutments D and the front faces of the pistons A with the result that the gaseous mixture is drawn into the chamber B through the pipes G and the ports G which as aforesaid are controlled by non return valves. As one abutment D moves away from one piston A in either of the chambers B it approaches the oppositely disposed piston A in that chamber and at the requisite moment the fixed cams-A will engage with the roller projections E on the rods I) during the rotation of the member or casing B so that the abutment disk D and the abutments D D are moved to enable the latter to enter their respective slots B in which they are retained while passing the fixed pistons. Immediate v the abutments I) I) pass the pistons A, i 2 the actuating rods E move away from the cams A so that the said abutments assume. their normal positions shown in Figs. 8 and 11 so that each abutment D which has drawn in a charge of the gaseous mixture at its rear face now commences to compress the charge drawn in by the preceding abutment between its front face and the rear face of the piston D which it is approaching; the compression of the charge continues until the front face of the abutment approaches near to the rear face. of piston when at the requisite moment the opening B in the ring valve B" registers with the fixed cross port A" see Figs. 5. (t and 7 so that the compressed mixture is transferred from the compressor chamber B at one side of the engine into the power chamber B at the other side at which time the abutment D in that chamber B is in the position shown in Fig. 8 quite close to the piston A so as to form a space to receive the compressed charge which is then ignited and thus causes the explosion or power stroke between the rear face of the abutment D and the front face of the piston so that the member or casing B carr ing the abutments is rotated. As the front face of each abutment I) approaches the rear face of each piston A in the same cylinder the cam A" actuates the rods E which oscillates the abutments so that they move into the slots B in passing the piston. The products of combustion are expelled from the chamber B by the abutments D being moved out of the slots 13* and being carried around by the rotation of the member or casing B so that the front face of each abut-ment in approaching the rear face of each piston forces the products of combustion through the exhaust ports B provided on the member or casing B seeaFig. 11. The exhaust gases then flow through the turbine blades B" and escape to atmosphere by the port B in the outer casing B After the exhaust through the ports B has been effected the abutments are moved into their slots B to pass the pistons and having passed them they are again caused to project into the power and com pressor chamber B ready to enable a charge 7 of compressed'mixture to be introduced between their rear faces and the adjacent pistons A, which charge is then ignited to enable the above cycle of operations to be effected. It will be understood that during the working of the engine the drawing in of the gaseous mixture and the compression of the same. by the abutments D is effected simultaneously with the explosion and exhausting of the gases in the power chamber B. Notwithstanding the two sides or parts of the engine one on each side of the middle ring or stationary member A being arranged at 90 degrees relatively to each other, the arrangement is such that the cycle of operations on both sides take place simultaneously that is to say the explosion at the two sparking. plugs on one side of the engine takes place at the same time as the explosion at the'two sparking plugs on the other side .so that the exhaust suction and compression movements or strokes on one side take place at the same time as the corresponding movements or strokes on the other side. The arrangement of the two similar parts on one side at 90 degrees insure uniform and even working and proper balance of the engine.

The diagram shown in Fig. 11 indicates the position of the pistons and abutments at the completion of the simultaneous exhaust and explosion stroke in each power chamber 18' and the completion of the suction and compression stroke in the compressor chambers B 1'. just prior to the abutment being actuated to move out of the way of the pistons. The figure may be regarded as a section on the line 33 of Fig. 1 and shows the parts on one side. of the stationary member A in full lines and the parts on the other side in dotted lines, and the arrows and descriptive words depicting the strokes at the two sides of the stationary member are shown in full and dotted lines to agree with the parts shown in full and dotted lines.

As aforesaid any suitable means may be provided for supplying the gaseous mixture, to the power chambers; for instance, a charge of air may be drawn into the compressor chambers by the compressor abutments and compressed in the said chambers so as to be supplied to the power chambers to min with. liquid fuel introduced through suitable jets, nozzles, or the like in the power chamber, to produce the exploslve mixture.

The means for supplying the compressedair or the compressed mixture to the power chambers instead of forming part of the rotary engine, may be exterior or separate.

Although an internal combustion rotary engine has been more particularly set forth, it will be understood that the engine can be adapted for operation by steam or other fluid, by making suitable modifications; for instance the steam may be supplied to the power chamber between the rear faces of the power abutments and the front faces of the power pistons and may be exhausted between the front faces of the abutments and the rear faces of the pistons. The pistons A? may be dispensed with or utilized as an additional set of power pistons and in conjunction with the abutments D The abutments may be operated by cam actuated rods such as E. The method of mounting the steam engine say on an aeroplane and the mounting of the propellers on the rotary member maybesimilar in general arrangement to that above set forth. In the case of, a steam engine the turbine could be employed either as an exhaust operated device or the turbine space could be utilized for heating air required for combustion in the boiler or generator furnace or burners.

What I claim and desire to secure by Letters Patent of the United States is 1. In a rotary engine, a stationary membeef-diametrically opposite pairs of fixed pistons on said stationary member, a rotary member forforming a casing for said stationary member, an annular chamber in said rotary member to receive said pairs of pistons, movable abutments on said rotary member, means carried by the rotary member for connecting the said abutments together and means forming part of the stationary member for engaging with and moving the said means which connect the abutments together. v

2. In a rotary engine, a stationary member, diametrically opposite pairs of laterally extending ,pistons on said stationary member, a two part rotary member forming a casing for said stationary member. said stationary member being provided with lateral extensions having bearings for said ro tary member, annular grooves in said rotary member receiving the pistons on said stationary member, diametrically opposite movable abutments on said rotary member adapted simultaneously to move into and out of said grooves, and means for moving said abutments comprising cams upon said stationary member.

3. A rotary engine comprising a stationary member, an inclosing rotary member, diametrically opposite pistons on said starotary member receiving said pistons, diametrically opposite movable abutments on said rotary member adapted to move into and out of said chambers, inlet ports on said stationary member, and exhaust ports in said rotary member.

4. In a rotary engine, ber, an inclosing rotary chambers in said rotary member, diametrically opposite istons on said stationary member fitting into said chambers, diametrically opposite movable abutments on said rotary member adapted to move into and out of the way of said pistons, and means for moving said abutments comprising cross rods connecting said abutments and cam members on said stationary member.

5. A rotary engine, comprising a stationary member, an inclosing rotary member, annular chambers in said rotar member, diametrically opposite pistons on said rotary member fitting into said chambers, diametrically opposite pairs of movable abutments on said rotary member adapted to move into and out of the Way of said pistons, and means for angularly moving said abutments comprising longitudinally and laterally displaceable rods connecting each pair of opposite abutments, and means on said rods for engaging cams on said stationary member.

6. In a rotary engine, a stationary member, pistons on each side thereof, a rotary member, a plurality of communicating chambers in said rotary member to receive said pistons, movable abutments on said rotary member located in the said chambers and on each side of the stationary member, and means for operating said abutments; the pistons, abutments, and means for moving the latter on one side of the stationary member being arranged at 90 to the corresponding parts on the other side.

7. In a rotary engine. a stationary memher having diametrically opposite fixed power pistons, a rotary member having a chamber to receive the said pistons and carrying diametrically opposite movable abutments. means carried by the rotary member for connecting the said abutments together, means forming part of the stationary member for engaging with and moving the said means which connect the abutments together, and means for supplying a gaseous charge to said chamber or chambers between the front face of each piston and the rear face of each abutment, the construction and arrangement being such that after the explosion has taken place the products of combustion are expelled from the said chamber by the front face of each abutment approaching the rear face of each piston.

8. A rotary engine of the type referred to constructed as an internal combustion engine comprising a stationary annular member a stationary memmember, annular having two diametrically opposite I)0\\'0I pistons and two diametrically opposite compressor pistons on each side thereof, a rotary memlbcr composed of two parts each having outer and inner annular grooves or chambers to receive respectively the power pistons and the compressor pistons, each part of the rotary member carrying diametrically opposite movable abutments, means for normally maintaining said abutments in the said annular chambers and means adapted to move the abutments from the chambers during the rotation of the rotary member.

9. A rotary engine, comprising a stationary member or ring having diametrically opposite fixed power pistons and diametrically opposite fixed compressor pistons on each side thereof, a rotary member having annular power chambers and compressor chambers in a rotary member, said rotary member carrying on each side thereof diametrically opposite disks each having a power abutnvent and a compressor abutment, cam actuated cross rods connecting said oppositely disposed disks whereby the disks are angularly oscillated during the rotation of the rotary member.

10. A rotary engine, comprising a stationary annular member having on each side thereof diametrically opposite compressor and power pistons, a rotary member having power and compression chambers to receive said pistons, movable power and compressor abutments normally maintained in said power and compression chambers, cross ports in the stationary member establishing conmunication between the compression chamber on one side of the stationary member and the power chamber on the other side of the stationary member, and rotary valves controlling said cross ports.

11. A rotary engine, comprising a member having diametrically opposite power pistons and diametrically opposite compressor pistons on one side thereof, and similarly (lisposcd power and compressor pistons on the other side thereof, the similar pistons on one side being arranged at 90 relatively to those on the'otlier side, a member comprising two parts each having concentric power and compression chambers in which said power and compressor pistons are fitted, diametrically opposite pairs of power and compressor abutments disposed in each part of said latter member normally located in the power and compression chambers, the two pairs of power and compressor abutments in one part being arranged at 90 to the corresponding abutments in the other part, cam actuated cross rods connected to each pair of power and compressor abutments in each part of said member. cross ports between the compression chambers and the power chambers, valves on the member carrying the abutments for controlling the cross ports and exhaust ports leading from the power cham- 1-1. A rotary engine as specified in claim- 3, in which the rotary member is provided on its exterior peripheral surface with a series of blades covered by a light metal casing, forming a turbine chamber, said chamber being in communication with the exhaust ports.

15. A rotary engine as specified in claim 4, a

in which the rotary member has formed on its exterior peripheral surface oppositely inclined blades with transverse slots concentrically arranged to produce a staggered passage through the blades, and a casing for said blades having outlet openings therein.

16. A rotary engine as set forth in claim 2, in which the stationary member carrying the pistons is provided with water cooling passages extending around said member, said passages communicating With passages in the pistons providing a water circulation through the stationary member and the pistons attached thereto.

17. A rotary engine as specified in claim 2, each of said pistons being provided with a passage communicating with a passage in the stationary member, and inclined slots communicating with said passage in the piston and terminating at the contacting faces of the piston and its chamber whereby lubrication may be effected.

18. A rotary engine as specified in claim 4, said stationary member being provided with openings to receive spark plugs, said openings being adjacent the front faces of the pistons.

19. A rotary engine as specified in claim 3, said rotary member having a propeller attached thereto.

20. A rotary engine as specified in claim 3, said rotary member having attached at each end thereof a propeller, said propellers being mounted on supports extending to the front and rear of the engine and being arranged at right angles to each other.

21. A rotary engine as specified in claim 2, said stationary member being provided with spaced suspension means.

22. A rotary engine as specified in claim 2, said engine having a central axial passage therethrough.

23. A rotary engine as specified in claim 3, said pistons \being formed with tapered or inclined chamber engaging surfaces.

24. A rotary engine as specified in claim 3, said pistons being provided with heat ground chamber engaging surfaces.

E. H. FRIEND. 

